Saline Hypertonic in Preschoolers

A growing body of evidence supports the importance of intervention in cystic fibrosis (CF) lung disease during early childhood, in order to potentially delay or prevent irreversible lung damage. Yet, aside from antimicrobial therapies, the CF community has no clinical trial evidence base with which to guide chronic pulmonary therapies in preschool children. Hypertonic saline (HS) is the most attractive chronic maintenance therapy to investigate in preschool children because it addresses defective mucociliary clearance, an early step in the cascade of events leading to CF lung disease that is expected to be abnormal prior to the onset of airway infection and inflammation. Based on several studies, HS appears to be safe in children less than 6 years of age, but its effectiveness has been difficult to measure. In a previous study (ISIS), children less than 6 years old receiving HS had the same number of lung infections as children receiving a control treatment. However, the investigators think that children this young need a more sensitive test, such as lung function testing, to see if HS works in preventing lung damage. Multiple Breath Washout (MBW) is a relatively easy lung function test to perform with preschool children. It calculates a measurement called the Lung Clearance Index (LCI), a sensitive measure of airway inhomogeneity. In a sub-study of the ISIS study in 25 children, LCI improved in children that inhaled HS twice daily for 48 weeks. This is a multicenter, randomized, double-blind, controlled, parallel group trial assessing LCI in children with CF ages 3 to 5 at enrollment. Participants will be randomized 1:1 to receive 7% HS (treatment arm) vs. 0.9 % isotonic saline (control arm) administered twice daily via jet nebulizer for 48 weeks. Study visits will occur at Screening, Enrollment, and at Weeks 12, 24, 36 and 48. Contact with a parent or legal guardian to assess adherence and interim medical history will occur at 1, 4 and 8 weeks after enrollment and then quarterly between subsequent study visits. Except for the screening visit, study visits will occur on a quarterly basis. Total duration of participation will be up to 52 weeks. As enrollment will occur over approximately 18 months, total duration of the study is expected to be up to 30 months (18 months enrollment plus 12 months for the last participants to complete study participation).